25. Chief Keef, 'Back From the Dead 2'

Chief Keef's work since 2012's Finally Rich remains, by and large, beneath the radar. Media fascination, restricted largely to his arrest record and controversies, has moved on. Yet the rapper has retained a creative restlessness and cohesive, evolving aesthetic. While rappers from Bobby Shmurda to Dej Loaf to O.T. Genasis build upon his older work to massive success, he's moved in new directions. On Back From the Dead 2, he became a rapper-producer, releasing a record that seethed with menacing, coiled energy. The bleak world from which he came still shapes his sound; it's a bleak and lonely record, with few guests and a darkly psychedelic shape formed by drugs and likely PTSD. Yet he finds a gleeful humanity inside the world's rotten core, with bluntly potent, economical rapping that gets strong mileage per word. D.D.